Noncentrosymmetric salt-inclusion chalcogenides (SICs) are a burgeoning class of second-order nonlinear optical (NLO) materials distinguished by their exceptional optical properties. These materials often exhibit robust second-harmonic generation (SHG) responses and possess wide band gaps that typically correspond to their impressive laser-induced damage threshold (LIDT). In this study, we present two isostructural salt-inclusion chalcogenides, namely [K₄Cl][Zn₁₁In₉S₂₆] (1) and [K₄Cl][Cd₁₁In₉S₂₆] (2), which consist of highly parallel-oriented host [M^II₁₁In₉S₂₆]³⁻ frameworks, with guest [K₄Cl]³⁺ ions incorporated to enhance structural stability and maintain charge balance. Notably, compounds 1 and 2 exhibit favorable NLO properties, including strong nonphase matching SHG intensities (1.9 and 5.7 × AgGaS₂ for particle sizes of 30–50 μm) under 1910 nm laser irradiation. Furthermore, compounds 1 and 2 demonstrate suitable band gaps (2.48 and 2.61 eV) and exhibit minimal anisotropy in their thermal expansion coefficients (ranging from 0.09 to 1.01), contributing to their significant LIDT (7.0 and 4.6 × AgGaS₂@1064 nm), respectively.

中文翻译：

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盐包合物硫化物 [K4Cl][MII11In9S26] (MII = Zn, Cd) 显示出强大的非线性光学活性

非中心对称盐包体硫属化物 (SIC) 是一类新兴的二阶非线性光学 (NLO) 材料，以其卓越的光学性能而著称。这些材料通常表现出强大的二次谐波产生 (SHG) 响应，并具有宽带隙，通常与其令人印象深刻的激光诱导损伤阈值 (LIDT) 相对应。在本研究中，我们提出了两种同结构盐包体硫属化物，即[K ₄ Cl][Zn ₁₁ In ₉ S ₂₆ ] ( 1 )和[K ₄ Cl][Cd ₁₁ In ₉ S ₂₆ ] ( 2 )，它们由高度平行定向的主体 [M ^II ₁₁ In ₉ S ₂₆ ] ³⁻框架，并掺入客体 [K ₄ Cl] ³⁺离子以增强结构稳定性并保持电荷平衡。值得注意的是，化合物1和2表现出良好的 NLO 性能，包括在 1910 nm 激光照射下强的非相位匹配 SHG 强度（粒径为 30-50 μm 时为1.9 和 5.7 × AgGaS ₂ ）。此外，化合物1和2表现出合适的带隙（2.48 和 2.61 eV），并在热膨胀系数上表现出最小的各向异性（范围从 0.09 到 1.01），从而实现了显着的 LIDT（7.0 和 4.6 × AgGaS ₂ @1064 nm），分别。